Added typing tree transformer framework

1 files changed, 40 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala b/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala
new file mode 100644
index 0000000000..99337f9db9
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala
@@ -0,0 +1,40 @@
+/* NSC -- new scala compiler
+ * Copyright 2005 LAMP/EPFL
+ * @author
+ */
+// $Id: TypingTransformers.scala 5359 2005-12-16 15:33:49Z dubochet $
+package scala.tools.nsc.transform;
+
+/** A base class for transforms.
+ *  A transform contains a compiler phase which applies a tree transformer.
+ */
+trait TypingTransformers {
+
+  val global: Global
+  import global._
+
+  abstract class TypingTransformer(unit: CompilationUnit) extends Transformer {
+    var localTyper: analyzer.Typer = analyzer.newTyper(analyzer.rootContext(unit))
+    private var curTree: Tree = _
+
+    override def atOwner[A](owner: Symbol)(trans: => A): A = {
+      val savedLocalTyper = localTyper
+      localTyper = localTyper.atOwner(curTree, owner)
+      val result = super.atOwner(owner)(trans)
+      localTyper = savedLocalTyper
+      result
+    }
+
+    override def transform(tree: Tree): Tree = {
+      curTree = tree
+      tree match {
+        case Template(_, _) =>
+          // enter template into context chain
+          atOwner(currentOwner) { super.transform(tree) }
+        case _ =>
+          super.transform(tree)
+      }
+    }
+  }
+}
+